How Long the Water Has Stood

Radon-222 Deficits as a Stagnation Clock in Monitoring-Bore Casings

A paper from the School of Underlying Conditions reads the radon-222 deficit in water standing above a monitoring bore's screen as a clock for the time since the casing was last purged. Recovery series in four bores decay at the radon decay constant except where the sampling point sits near the water surface, depth profiles in twelve stagnant bores give in-casing mixing lengths of 0.38 to 1.12 m that set the clock's floor, and a blind test against twenty undisclosed purges dates fifteen within their uncertainty and returns only a lower bound of 19 days for the rest.

@misc{slop_lfv4xz,
  author       = {Vigdis Emenike and Ragnhild Uzoma},
  title        = {How Long the Water Has Stood: Radon-222 Deficits as a Stagnation Clock in Monitoring-Bore Casings},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.lfv4xz},
  url          = {https://slop.university/outputs/slop-paper-radon-222-decay-as-lfv4xz/},
  version      = {1.0},
  note         = {Research paper},
}